Controlling liquid-insulated electric apparatus



Sept. 13, 9 BUCHHOLZY CONTROLLING LIQUID INSULATED ELECTRIC APPARATUS Original Filed Sept. 15, 1922 b //7 wen/or Max Bacbbo/z PATENT OFFICE.

x wa qassn'n, enn'manx.

'cozrrnonnrnngnrenrn-rnsunarnn annc'rnrc arraaarus.

' Original .jppnalaa nledseptember15,'1922,seria1 No. anus-z, and in Germany January 19, 1922. i l ,Dljl ded and-this'appllcation Med Apr 16, 1925. Serial No. 28,672.

invention has reference to a method and means for; protecting electric apparatus operating in an insulating liquid, such as 011 transformers,'o1l switches, grounding throttling coils, resistances and the like, and it is one of the. important objects of my invention to provide a device of very simple construction and great reliability and adapted to operate before extensive in uries "to l the aparatus to be protected can occur by sparklng, overloading or other disturbances.

My invention particularly based on the fact that in the case of disturbances in the operation of the apparatus to be protected or in the case of sparking or other lrregularities of operation, or whenever such irregularities are imminent. as well as in the case of any ebullition or fermentation processes in theoil, serving as an insulating liquid,

bubbles of gases of decomposition are formedf which can operate protective means, for instance an electric contact, either a working or a closed contact, which is ,adapted to switch out of circuit the apparatus to be protected, or which will operate an alarm or annunciator device indicating the disturbance, or which is adapted to effect both kinds of operations. The gases formed by decom'-" position may influence the protective means in different ways, this application being a division of my copending application Serial Number 588,457 filed September 15, 1922.

I may for instance utilize the movements of parts of the liquid arising in consequence of a change of volume or t 1e expanslon of the liquid or from other causes incident upon the generation of the gases or oil vapors for varying the operative conditions of a protective circuit.

40 In the drawings aflixed to this specification and forming part thereof, a device embodying my invention is illustrated diagram-.

matical y by way of example.

In the drawings Fig. 1 shows a rotective device with a contact adapted to. closed by a movement in the insulating liquid in a transformer vessel, while Fig. 2 is a plan view of the contact floats.

In the drawings a is the transformer vessel, 6 is the core of the transformer, c are the windings, d are the leading-in insulations for the conductors, e is the oil switch, f is the releasing coil connected with it and g is a source of current which upon and D, the float C being considerably larger 'eflected' both within as well as outside 0 the operation of the safety device excites the coil, opens the oil switch and causes the switching-out of the apparatus.

The transformer vessel a, which is en: tirely filled with oil, is in communication with an expansion vessel n. The wire'sof the protective circuit extend through a side wall of the expansion vessel and are connected each with one of a pair of floats C than float D and the two floats being connected by links F, while float C is attached to theside wall of the vessel 11. by links E. On the large float C is mounted a contact piece G extending above and in close. proximity to another contact piece on the upper surface of float D which is connected to the other terminal of the protective circuit, the

Hosts being thus insulated from each other.

If a liberation of gases of decomposition in the transformer vessel a causes agitation of the insulating liquid movement, this will act on the two floats C and D in a different manner. For while float C is attached to the wall of the vessel and has a larger mass it will be less movable than the small 'float D linked to it and which, owing to its very small mass is easily movable. In consequence thereof a sudden movement will cause the small float D to be rocked before the large float Chas had time to be set moving, and float D will therefore establish a contact with the piece G, thereby operating the opening of the oil switch eand throwing the transformer out of operation. Other movements of the liquid particles caused by a liberationof gases or vapours will act in a similar way.

The contacting device according to this invention may be arranged at different places, either in the interior of the main oil receptacle or, in the case of transformers, in combination with expansion vessels con-. tained therein, or s cial spaces, tubes or similar instrumentahties may be provided adapted for the reception of the contacting devlces. The closing of the circuit may}? liquid. 7

The circuit to be controlled by the contacts referred to may excite either. directly or by the medium of an intermedi to relay the releasing coil of an oil switch which interrupts the endangered circuit. In theoasc of apparatus the circuit of which does not include an oil switch, as frequently occurs,

electric apparatus comprising a container for for instance in the cases 0]": transformers mounted in the field at wide distances apart,

other provisions should be made for the pur poses of this invention.

Besides the form of construction herein shown and described, the. invention is susceptible of a variety of other modifications and forms of application of the principle of my invention all of which operate substantially in a similar manner. The means of connectingthe contacting device with the releasing circuit and the switching means are open to changes and alterations without any material importance for the operation of the apparatus according to my invention which in its broad aspects comprises the operation of safety devices for electric apparatus or the like, adapted for operation by vapors, fumes, gases or similar emanations liberated an'd expelled from the insulating medium, and means adapted to be operatively influenced by such emanations, and connected to fuses or equivalent safety means, the instrumentalities shown and described in thisspecification as embodiments of these principles be-.

ing susceptible of modifications without deviating from the spirit of my invention as set forth in the claims. a

In the claims the term .gases is meant to comprise also vapors and fumes.

I claim 1; Protective system for liquid-insulated electric apparatus comprising a container in said container surrounding sai and a supply of insulating liquid surrounding the apparatus to be protected, a protective circuit and means adapted to be operated by an agitation of the liquid occurring in consequence of a decomposition of such liquid, for varying the operative conditions agitation to vary the operative conditions of of said circuit.

2. Protective system for liquid-insulated electric apparatus comprising a container for said apparatus, a supply of insulatin liquid ratus, a protective circuit, and a'contact' device fioating on said liquid and adapted to be 1 actuated by agitation of the liquid occurring in consequence of a decomposition of such liquid for varying the operative conditions of said circuit.

ti-Protective' system for liquid-insulated quence of a decomposition of such liquid for varying the operative conditions of said circuit.

I 4. Protective system for liquid-insulated electric apparatus comprising a container and a supply of insulating liquid, surr0unding the apparatus to be protected, a protective circuit, a large float on the surface of said liquid, means limiting the movements of said large float, a small float linked to said large float and means for varying the operative conditions of'said circuit on the" small float'being displaced relativelyto the large float.

5. Protective system for liquid-insulated electric ap aratus comprising a container and a supp y of insulating liquid, surrounding the apparatus to be protected, a protec tive circuit, an expansion vessel communicating with said container, a large float on the surface of the liquidin said expansion vessel, and linkedtp the wall thereoffa small float linked to said large float and means for varying the operative conditions of said circuit on the small-float beingdisplaced relatively-,- to the large float.

6. The. method of controlling abnormal working conditions of liquid insulated ap paratus which comprises-causing a decomposition occurring in the liquid to produce an agitation of said liquid, and causing the a protective means.

7. The method of controlling abnormalworking conditions of. liquid insulated apparatus which comprises causing a decomposition occurring'm the liquid to produce an agitation of said liquid, and causing the agitation to vary the operative conditions of a rotective'circuit. a

= n testimony whereof I aflix my signature.

MAX BUCHHOLZ. 

